Automotive Ethernet Line Coding With FEC and Scrambling Under Severe Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed data networks face challenges in maintaining robust communication under severe external noises such as narrow band interferences, mechanical vibrations, and electrostatic discharges, which can disrupt data transmission and require improved packet handling and path resolution.
Innovation Solution
The implementation of a robust line coding scheme using non-complex bit-to-symbol mapping, forward error correction (FEC) coding, and an additive bit scrambler, along with specific signal constellations and clock structures, to enhance data transmission reliability over noisy communication links like automotive Ethernet PHY over single unshielded twisted pair (UTP) cables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional line coding schemes are used for high-speed data transmission, then data transmission rate can be achieved, but communication reliability deteriorates under severe external noises
Solution Approach 1:
The patent applies preliminary action by performing forward error correction (FEC) coding on the data stream before transmission. The FEC encoder adds redundant bits to the data in advance, enabling the receiver to detect and correct errors caused by external noises without requiring retransmission, thus maintaining communication reliability under noisy conditions.
Solution Approach 2:
The patent introduces an intermediary approach by using a scrambled data stream as an intermediate representation between the original data and the transmitted signal. The scrambler transforms the data into a pseudorandom sequence that is more resilient to noise, and the descrambler at the receiver restores the original data, effectively mediating the transmission process to withstand severe external noises.
2Reliability
If complex error correction codes are implemented, then communication reliability improves, but device complexity increases
Solution Approach 1:
The patent segments the error protection function into two distinct components: forward error correction (FEC) coding and scrambling. This segmentation allows each component to perform a specific function with optimized complexity - FEC handles systematic error correction while scrambling provides additional noise resilience, together achieving high reliability without requiring a single overly complex coding scheme.
Solution Approach 2:
The patent employs parameter changes by using different scrambling polynomials and FEC code rates adapted to specific transmission conditions. This allows the system to adjust the balance between complexity and reliability based on the noise environment, selecting appropriate parameters to achieve the required communication reliability without unnecessarily increasing device complexity.
3Object-affected harmful factors
If robust line coding with FEC and scrambling is used, then noise immunity improves, but processing complexity increases
Solution Approach 1:
The patent applies preliminary action by performing all error correction coding and scrambling operations at the transmitter before transmission. This eliminates the need for complex iterative error correction algorithms at the receiver, shifting the processing complexity to the transmitter where it can be managed more efficiently and reducing the receiver's processing burden.
Solution Approach 2:
The patent uses the scrambled data stream as an intermediary that simplifies subsequent processing. The scrambling transformation converts the data into a form that has favorable spectral properties and is more amenable to simple filtering and equalization operations, thereby reducing overall signal processing complexity while maintaining noise immunity.
4Productivity
If high data transmission rate is maintained, then network performance improves, but susceptibility to external noises increases
Solution Approach 1:
The patent applies preliminary action by encoding error correction bits and applying scrambling to the data stream before transmission at high data rates. This preliminary processing ensures that even when data is transmitted quickly without extensive error checking during transmission, the receiver can reliably reconstruct the original data using the pre-added redundancy and scrambling properties, maintaining communication stability at high speeds.
Data Source
AI summary
A system to implement a communication line coding scheme using a non-complex bit-to-symbol mapping, a forward error correction (FEC) coding, and an additive bit scrambler after the FEC at the PHY layer is provided. The system may be a part of or implemented by an automobile component. The system may be a PHY device configured to convert data from the MAC layer into 2D-PAM3 symbols that are transmitted across a communication link at a predetermined transmission rate, such as to be compliant with a communication standard. The PHY device may select characteristics of the conversion, such as the FEC coded symbol, based on the target transmission rate. The PHY device may include a transceiver, and may convert the data from MAC layer to PHY layer and back.